One of the first companies to reveal its plans for Power over Lan is PowerDsine which is supporting the IEEE 802.3af standard in its Series 6000 Ethernet hubs. The intelligent hubs not only pass data to client nodes across Category 5 cables but also use the link to supply electrical power. This means that an 802.3af-compliant laptop will be able to use a single cable rather than having to use a Lan cable, mains supply and power adaptor.
Igal Rotem, chief executive at PowerDsine, believes the advantages of Power over Lan will revolutionise the roll out of networks. "A good measure of the savings on offer can be shown by the example of installing a wireless Lan access point. At the moment, the IT installer has to provide an RJ-45 cable connection and an electrician has to connect the power. With Power over Lan the job can be done by the IT installer with a single cable, which, more often than not, has already been installed," he said.
The key to the PowerDsine implementation is the ability for the hub to detect whether the connected system, which could be a laptop, access point, or webcam, is enabled for Power over Lan. This circuitry also acts like an intelligent fuse, because a malfunctioning device will try to draw too much current. The hub detects this, cuts the power supply and can send an alarm to a network management system.
Other suppliers, including switch makers Cisco and Extreme, are planning to incorporate 802.3af specifications in their products. Network specialist Avaya has already given the PowerDsine hubs a thorough testing as part of its network structure for the recent World Cup competition in Korea and Japan.